بررسی اثرات زیرکشندگی کنه کش کلرفناپیر بر فراسنجه های زیستی کنه تارتن دولکه‌ای Tetranychus urticae (Acari: Tetranychidae) و کنه های شکارگر Phytoseiulus persimilis و Neoseiulus californicus (Acari: Phytoseiidae)

The two-spotted spider mite (Tetranychus urticae Koch) is a major pest of various plants worldwide. The extensive use of chemical compounds has led to the development of resistance in this pest, making biological control a viable alternative. Phytoseiulus persimilis Athias-Henriot and Neoseiulus californicus McGregor are important predators of the two-spotted spider mite. This study investigated the effects of chlorfenapyr, an effective acaricide against the two-spotted spider mite, on this pest and its two predators under laboratory conditions. The LC50 values of chlorfenapyr for T. urticae, P. persimilis, and N. californicus were estimated as 77.72, 536.22, and 1186 ppm, respectively. The effects of sublethal concentrations (LC10, LC20, and LC30) of chlorfenapyr on all three species were analyzed based on the two-sex life table theory using the Twosex-MSChart software. The results revealed a significant decrease in larval emergence time for T. urticae at the LC30 concentration compared to the control, while no significant changes were observed in the predatory mites. Additionally, the lifespan of T. urticae was significantly reduced across all tested concentrations, and for P. persimilis, a significant decrease was observed from the LC20 concentration, and for N. californicus, from the LC10 concentration. The oviposition period for all species significantly decreased from the LC20 concentration and above. Fecundity also showed a significant decline, starting from LC10 for T. urticae and P. persimilis and LC20 for N. californicus. Moreover, all three species exhibited significant reductions in reproductive parameters (GRR, R0, r, and T) from the LC20 concentration onwards compared to the control. These findings suggest that chlorfenapyr is highly toxic to the two-spotted spider mite, enabling effective control at low concentrations. While moderately toxic to P. persimilis, it appears to have minimal impact on N. californicus at field-relevant concentrations, making it a promising candidate for integration into IPM programs.